A lumbar sympathectomy was performed on 36 patients with angiographical verified arterial occlusion on the upper and lower leg. Pre- and postoperative partly the lower leg flow was registered by air plethysmography and the lower leg and bridge of foot flow simultaneously registered by the Straine gauge plethysmography. Independent of the method an increase of the arterial blood flow was noticed with 40% of the patients. In spite of this improvement the registered values after the reactive hyperemia in lower leg and bridge of foot are still clearly restricted. The remaining 60% of the patients however showed a clear worthening of the blood flow conditions.